I will admit that I have no idea how that would look like. If quantum computer can be as capable as one envisioned in Jormungand, I am not sure if anything short of declaring them a weapon is needed.
Quantum computers aren't magic, they have specific capabilities that can be planned around. Google 'post-quantum cryptography' for current work on quantum resistent algorithms, some of which are already being deployed to production.
Any sufficiently advanced technology is indistinguishable from magic. I will openly say that I not understand it beyond knowing that, in a very general sense, it is not based on ones and zeroes. If I do not understand it, it is difficult for me to wrap my head around it and what it can and cannot do.
It might not be magic, but it might as well be ( and may end up being next hype train ).
